University of Wisconsin School of Medicine and Public Health, Department of Family Medicine, Appleton, WI, USA

Abstract: Resistant hypertension, defined as failure to achieve target blood pressure despite the use of optimal or maximum doses of at least 3 agents, one of which is a diuretic, or requiring 4 or more medications to achieve blood pressure goal, is likely to affect up to 20% of all patients with hypertension. Apparent resistant hypertension may be caused by medication nonadherence, substances that either interfere with antihypertensive mediations or cause blood pressure elevation, and under- or inappropriate medication treatment. Certain patient characteristics are associated with the presence of resistant hypertension and include chronic kidney disease, diabetes, obesity, and presence of end-organ damage (microalbuminuria, retinopathy, left-ventricular hypertrophy). Secondary causes of resistant hypertension are not uncommon and include obstructive sleep apnea, chronic kidney disease, primary aldosteronism, renal artery stenosis, pheochromocytoma, and Cushing’s disease. Initial medication management usually includes adding or increasing the dose of a diuretic, which is effective in lowering the blood pressure of a large number of patients with resistant hypertension. Additional management options include maximizing lifestyle modification, combination therapy of antihypertensive agents depending on individual patient characteristics, adding less-commonly used fourth- or fifth-line antihypertensive agents, and referral to a hypertension specialist.